Argentine researchers are studying means of capturing cow methane

Grazing by cows or sheep can cut emissions of nitrous oxide — a powerful greenhouse gas — in grasslands from China to the United States, according to a study that overturns past belief that farm animals stoke releases.

Adding to understanding of links between agriculture and global warming, the report in…the journal Nature said livestock can help to limit microbes in the soil that generate the gas, also known as laughing gas.

“It’s been generally assumed that if you increase livestock numbers you get a rise in emissions of nitrous oxide. This is not the case,” said Klaus Butterbach-Bahl of the Karlsruhe Institute of Technology in Germany who was among the authors.

Laughing gas is one of several heat-trapping gases linked to farm animals and the scientists said there was a need for more study to see how far their findings would affect agriculture’s total impact on climate change.

Emissions of the gas account for 6-8 percent of global warming from human activities, making it the third most important greenhouse gas after carbon dioxide and methane, he said. Estimated nitrous oxide emissions from temperate grasslands account for 1-2 percent of the total…

Grasslands subject to winter frosts where such gas emissions may have been overestimated make up an area the size of India, or about a third of the world’s temperate grasslands that cover about 10 million square kms (3.9 million sq miles).

But the study did not look, for instance, at other damaging climate impacts of livestock. Goats, buffalo, cows and sheep also release heat-trapping methane as they digest food.

Ah-hah! They didn’t allow for methane which some researchers think could be collected for commercial use. No matter which end it comes from.